Frequency: This refers to the number of vibrations per second and is measured in hertz (Hz). Higher frequencies result in higher-pitched sounds, while lower frequencies produce lower-pitched sounds.
Soundenergy is produced when an object vibrates, creating disturbances in the surrounding medium. These disturbances travel as waves, carrying the energy of the sound. When the waves reach our ears, they cause our eardrums to vibrate, which our brain interprets as sound.
The student demonstrates an understanding of the forces that shape Earth by identifying and comparing a variety of Earth's land features (i.e., rivers, deltas, lakes, glaciers, mountains, valleys, and islands).